Pneumatic tire and method of manufacturing same

A pneumatic tire comprising:

• a tread portion provided with a land portion having a top surface for contacting with the ground,
• the land portion having a first side surface extending radially inwardly from a first axial edge of the top surface, and a second side surface extending radially inwardly from a second axial edge of the top surface,
• the land portion provided with a conductive portion made of a conductive rubber,
• the conductive portion having a radially outer end exposed in said top surface, and a radially inner end electrically connected to a conductive internal structure of the tire which is to be electrically connected to a wheel rim when the tire is mounted on the wheel rim,
• wherein
• in a cross section of the land portion taken along a plane including the rotational axis of the tire,
• the conductive portion inclines to the first side surface of the land portion toward the radially outer end from the radially inner end of the conductive portion, so that the radially outer end of the conductive portion is closer to the first axial edge than the second axial edge, and
• the angle between the conductive portion and said top surface is not less than 40 degrees and not more than 90 degrees,
• wherein
• the first side surface comprises a radially inner part and a radially outer part extending from the radially inner part to the first axial edge while inclining to the conductive portion at an inclination angle being larger than an inclination angle of the radially inner part,
• in said cross section of the land portion, a radial height of said radially outer part of the first side surface is in a range from 30% to 60% of the radial height of the land portion, and
• in said cross section of the land portion, an area surrounded by said radially outer part, an axially extended line of said top surface and a radially outwardly extended line of said radially inner part is in a range from 1.0% to 2.5% of an overall area of the land portion,
• wherein
• said top surface of the land portion is provided with:
• first center lug grooves extending from the first axial edge toward the conductive portion and terminating without intersecting the conductive portion in the top surface of the land portion, and
• second center lug grooves extending from the second axial edge toward the conductive portion and terminating without intersecting the conductive portion in the top surface of the land portion, whereby the land portion is formed as a circumferentially continuous rib,
• wherein
• the first center lug grooves and the second center lug grooves are arranged alternately in the tire circumferential direction,
• the first center lug grooves and the second center lug grooves are inclined in the same direction with respect to the tire axial direction,
• the second center lug grooves extend while curving toward one direction and inclining with respect to the tire axial direction, whereas the first center lug grooves extend straight, and
• the first center lug grooves have a length, and the second center lug grooves have a length greater than the length of the first center lug grooves, and
• wherein
• the first center lug grooves are respectively connected to chamfered portions intermittently formed on the first axial edge by the radially outer part of the first side surface,
• the chamfered portions have a substantially constant axial width W1 along their respective entire lengths in the tire circumferential direction, and the axial width W1 is in a range from 1.5 mm to 2.5 mm, and
• the distance between the chamfered portions and the radially outer end of the conductive portion is in a range from 1.5 to 2.5 mm at the top surface of the land portion.